Just bought 1930 MODEL A five window coupe. I'm looking to install a 2 inch drop front cross member and a four inch drop axle. Say if running 15 inch tires all the way round. How much will the rear cross member need to drop or Z ed to make the car sit level? I'm thinking of buying the rear cross from speedway. This car is going to be fenderless. I see pics of the rear cross sitting right on top of the frame, probably creating a four inch Z in rear. I will be running coil overs on rear. Hope there is someone who can help me with the correct ride height or stance.
I’m sorry to say but your gonna have to mock it all up and find out. Rim size doesn’t mean shit when there’s a billion tire sizes available. Best bet to get you a lose idea of what your going to need to do is post photos on this thread of cars you like and want yours to look like and we can tell you what’s - most likely- been done to get them like that
A 2" drop front crossmember on a Model A is essentially flat. Is that what you really mean? If so, be aware that most repro radiators will hang down a little between the feet, and might not leave room for your spring clamp. Especially important to have the tank in the right spot on an A because if the bottom tank is too high it will show in the grille shell (=ugly).
I bought the chassis with the car and someone had already removed the front cross member. Just thinking someone might have experience with using the Speedway two inch drop cross member with a four inch drop axle.
As far as I believe, the 2 inch drop reference is only relevant if the A x member is being fitted into B rails. .. A 4 inch drop axle is only 3 inches lower than a stock one as there is an inch of drop in a stock axle .. Just so you remember to take that into account when doing your calculations .. without much in the way of heavy chassis mods if using coilovers you can drop the lower mount relative to the axle and raise the top mount in the chassis ( within reason) without chopping the frame to bits .. likewise coil over length .. That would facilitate a lower stance .. more than one way to skin a cat .. using coilovers though ... is that traditional ( thats a dig but I did wink as well : ) )
Really just wanting a good ride if possible. I plan on channeling the body four inches. Thats my gold to keep frame as stock as possible, but lower the car. Wish I had a few pics from others with same mods. Coil overs should ride better than spring?
each can ride as good or bad as each other , the trick is selecting the correct length and spring rate .. That is true for both leaf springs and coil overs. With coil overs you will need to consider axle location. By that I mean make sure it doesnt wander side to side or flip around its own axis .. So with coils you need to consider ways to keep the axle from parting ways with the car , yet be compliant enough to move with the suspension .. There is tons of info on the subject and unfortunately the only way to learn is to search out the info read it understand it and have a go.. getting it wrong isnt wrong, its called learning Sounds like your about to embark on a steep learning curve ... Dont worry about it, we have all been there, indeed, every project brings its own issues regardless of how long youve been doing this or how clever we might think we are, were often stumped !
If you are needing to buy crossmembers and chassis parts, Try looking at other places besides speedway. For example, some of the repo front crossmembers out there are meant to be welded into boxing plates, not attached to the frame with rivets as original. Not that you have to use rivets, but now for you to put the crossmember in you need to put boxing plates in first. I know So Cal Speed Shop sells a front crossmember that is wide enough to go all the way from the inside to inside wall of the frame. you can still box around it but you can mock it all together with bolts and square everything before you ever plug you welder in. The cost may be slightly more from So Cal, but when it takes you 2 days to get to the point of putting in that 60 dollar crossmember, the 90 dollar one from So Cal would have taken about an hour. Food for thought. try looking at R-Jays Speed Shop, Pete and Jakes, So Cal and Posies for chassis parts. The quality is much higher. and will give you a much better end result. There are a ton of cars out there that have been put together with Speedway stuff that are fine, but just not quite right or not what the builder really wanted. Speedway has its place.....but there is a reason it is the Wal Mart of hot rod stuff. I highly recommend R Jays Speed Shop. His stuff is top quality and you can not beat the price. Give him a call, and tell him what you are wanting to do, and he can recommend what the best path would be. he builds some really nice stuff. https://rjays.com/
A few pics of my chassis, Unsure of front cross member manufacture - might be Speedway but it is heavy duty, was not full width but didn't matter to me, also had to use a thick steel plate as a spring clamp as radiator was hitting original spring clamp. Axle is 4 inch drop, chassis kicked up heaps at rear, I did not start with original chassis so I cannot say how far rear is kicked up. Car has approx 4 inch channel and I have made rear ride height adjustable in one inch increments at the shock mounts. Hope this helps. Glen
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